Artificial limb



March 4, 4 E. c. CARTER 7 2,416,817

ARTIFICIAL LIMB Filed March 5, 1945 2 Sheets-Sheet 1 I n uentor Z'dwzirz- C. Carter;

wnlunnlpm March 4, 1947. C CARTER I 2,416,817

ARTIFICIAL LIMB Filed Marbh 5, 1945 ZSheets-Sheet 2 Inventor Patented Mar. 4, 19 47 UNITED STATES PATENT OFFICE V ARTIFICIAL LIMB Edwin 0. Carter, Rio dame City,Tex. Application March 5, 1945, Serial No. 580,975;

1 Claim. 1

This invention relates to an artificial limb, and more particularly to a joint for such a limb.

The primary object of this invention is the provision of an improved joint for an artificial limb, so constructed and arranged as to give the wearer of such a limb a minimum of discomfort, while walking on uneven or irregular surfaces.

An additional object of the invention is the provision of such a joint which will provide, in effect, a cushioning surface for the wearer of an artificial leg.

A still further object of the invention is the provision of such a joint which will not allow the foot of an artificial leg, for example, to twist out of line upwardly or sidewardly. Still another object of the invention is the provision of such a joint which will hold the foot of an artificial leg in fixed position until weight or pressure is applied, and will then respond in any direction the wearer may wish. A still further object of the invention is the pro-vision of such a device characterized by extreme simplicity in manufacture, which will be sturdy and durable in construction, and reliable and efficient in operation.

Other objects will in part be obvious and in part be pointed out as the description of the invention proceeds and shown in the accompanying drawing wherein I have disclosed preferred embodiments of this inventive concept.

In the drawings:

Figure 1 is a side elevational view of the foot of an artificial leg showing the device of the instant invention applied thereto,

Figure 2 is a top plan view of the device disclosed in Figure 1,

Figure 3 is a sectional View taken substantially along the line of Figure l as viewed in the direction indicated by the arrows,

Figure l is a sectional view taken substantially along the line li of Figure 2 as viewed in the direction indicated by the arrows,

Figure 5 is a side elevational view of a modified form of construction, and

Figure 6 is a side elevational view of a still further modification.

Similar reference characters refer to similar parts throughout the several views of the drawings. I

Having reference now to the drawings, there is generally indicated at it an artificial foot, comprised of a heel portion H, and a toe portion i2 secured in spaced relation to a base plate l3 as by screws It or the like, and so spaced as to define a relatively wide aperture therebetween, the

aperture being tapered upwardly toward the front and rear, as indicated at l5 and i6.

Suitably secured to the base plate it, as by welding or in any other desired manner, is a relatively heavy coil spring H, which extends upwardly to a point adjacent the top of the aperture between the heel and toe portions, I l and l 2. Suitably secured to the top of the spring IT is a plate I 8, to which, in turn, is secured the upper section I9 of an artificial leg.

The spring I! is designed to support the weight of the wearer, and perhaps ten to twenty per cent additional weight in a semi-compressed, but not fully compressed position. It will be seen that the configuration of the spring is such. as to permit the foot readily to adapt itself to irregular surfaces, and to twist to the front and rear or sideways, as may be necessary, but only when the weight of the wearer is applied thereto. The weight of the spring is sufiicient, when the le is lifted from the ground, to hold the foot in a normal and aligned position.

While in the foregoing the particular joint of the instant invention has been shown as disclosed in connection with an ankle joint of an artificial foot, it will be readily understood that the same may be applied, as best shown in Figures 5 and 6, to other usages. Figure 5 discloses an artificial limb, generally indicated at 25, comprised of a thigh section 25, a calf section 2?, and a foot section 28. In this modification the calf section 21 is capped by a metal plate 29, to which is secured a spring 39 similar to the spring II, the upper portion of which, in turn, is capped by a metal plate 3! secured to the lower portion of the thigh section. In this modification, it will be readily seen that the spring 3t serves effectively to act as a knee joint. If desired or necessary, a second spring, corresponding to the spring ll, may be positioned between the foot portion and the calf portion.

In the modification disclosed in Figure 6, an

artificial arm is indicated comprised of an upper portion M1 and a lower portion 4|, between which is positioned a spring 62, capped by end plates 43 and 44 secured to the extremities of the two sections, and positioned in the locality normally occupied by the elbow joint.

Obviously, wrist or other joints may likewise be constructed in the manner above disclosed.

The device of the instant invention may be constructed of any resilient metal, of sufficient strength to support the weight of the wearer plus a slight overage, and may be made in a Variety of sizes and forms 'to accommodate various weight of the users. 7 From the foregoing, it will now be seenthat there is herein provided a device accomplishing all of the objects of this invention, and others including many advantages of great practical utility and commercial importance.

As many embodiments may be made of this inventive concept, and as many modifications may be made in the embodiment hereinbefore shown and described, it is to be understood that all matter herein is to be interpreted merely as illustrative and not in a limiting sense.

I claim: A joint for artificial limbs including spaced foot and heel portions, a ground engaging plate secured to said foot and heel portions, a compressible coil spring secured to the upper surface of said plate being engageable with the adjacent 4 edges of said foot and heel portions for limiting the movement of said limb, an end cap secured to the upper end of said spring, and a leg por- The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,315,795 Johnson et a1 Apr. 6, 1943 83,496 Head Oct. 27, 1868 FOREIGN PATENTS Number 7 Country Date 483,373 French Apr. 6, 1917 24,113 German 

